This invention relates generally to control systems for motor vehicles, and more particularly to integrated electronic motor vehicle management and control systems specifically useful in heavy duty vehicles such as trucks, in which various engine and vehicle functions such as engine timing and speed control, road speed control, vehicle safety functions, fuel exhaust emissions monitoring, fuel economy and diagnostic and maintenance functions are performed and monitored by an integrated microprocessor based control module system.
In the past, most engine and vehicle control functions in heavy duty vehicles were performed mechanically in response to very simple parameters such as engine speed. The execution of such functions was thus limited and optimization in terms of fuel economy, engine performance and engine emissions quantities was not possible. In addition, certain diagnostic and maintenance functions were left to human performance and thus such functions were not necessarily performed optimally or performed in a manner interrelated with the performance and parameters of other vehicle functions.